Shielded connector for movable lines



5,1959 L.A. HARRIS ET 3,459,873 I SHIELDED CONNECTOR FOR MOVABLE LINESFiled Feb. 16, 1967 If'rvervtor-si Lawrence A.Hd.r-r-'is Arthur N. DeTom mdSI,

.b d. M

y Their Attorney.

United States Patent 3,459,873 SHIELDED CONNECTOR FOR MGVABLE LINESLawrence A. Harris, Schenectady, and Arthur N. De Tommasi, Newtonville,N.Y., assigncrs to General Electric Company, a corporation of New YorkFiled Feb. 16, 1967, Ser. No. 616,687 Int. Cl. H02g 15/18 US. Cl. 174863 Claims ABSTRACT OF THE DISCLOSURE To provide a shielded flexibleconnection for two coaxial lines, two conductive balls with diametricalaper tures are inserted over each of the two coaxial lines, a wire isconnected between the inner conductors of each of the two coaxial lines,conductive tubular members form a socket for each of the conductiveballs and are engaged with screw threads to shield the connecting wire,and a tubular insulator within the tubular members encircles the 'wireand separates the conductive balls.

This invention relates to a shielded connector for shielded conductors,and more particularly, to a shielded connector allowing angulardisplacement of the axes of shielded conductors.

In many electronic vacuum systems utilized in experimental andindustrial apparatus, it is necessary to shield various conductors.These conductors may require shielding for one of two reasons. First,very small currents carried by the wires are subject to seriousdisturbances caused by stray electrons or ions within the systemstriking the wires. Second, those wires of the systems which are at ahigh electrical potential may create fields which would seriously impairthe desired characteristics of the phenomenon occurring within thevacuum system.

Not only is it necessary that the wires be shielded, but it is equallynecessary that all connections between the Wires be shielded. While aconventional coaxial line satisfies the requirement of the shieldedwire, the requirement of the shielded connector is somewhat moreditficult since the connection itself should retain some degree offlexibility to accommodate the connection of shielded conductors withangularly displaced axes.

In addition, the shielded wire and connectors must withstand rather hightemperatures within the vacuum system without giving off contaminatingvapors. Of course, contaminating vapors within the vacuum system wouldalso greatly impair the desired characteristics of the phenomenon withinthe systems. In the art, this ability to withstand the high temperaturesof the vacuum system without giving cit contaminating gases is termedbakeability. Commercially available flexible coaxial cables have organicinsulation which is not bakable. The need for bakeability restricts thematerials to metals and inoganic insulators such as glass or ceramicwhich are inflexible.

In the prior art, the desired characteristics of flexibility andbakeability of shielded electrical connections have achieved byutilizing a series of hollow insulating beads inside a copper braid.While this method was effective to some degree, the braid was generallyundesirable since the shielding was not complete and the many fine wiresin the copper braid were difiicult to control.

Although various ball and socket arrangements have been utilized forconnecting coaxial cables for RF transmission, many are expensive and/ornot easily disconnected.

Accordingly, it is an object of this invention to provide a flexibleconnection between inflexible sections of a shielded conductor.

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It is another object of this invention to provide a flexible connectionhaving a high degree of bakeability.

It is still a further object of this invention to provide a shieldedconnector which is simplified and may be readily disconnected oradjusted.

Briefly, in accordance with one form of this invention, there isprovided a shielded connector which allows for angular displacement ofthe axes between a first shielded conductor comprising inner and outerconductors and a second shielded conductor comprising inner and outerconductors. The shielded connector comprises conductive balls withapertures through which the shielded conductors are inserted makingelectrical contact therewith and a flexible conductive memberelectrically connecting the inner conductors of the shielded conductors.The conductive balls are separated by a tubular inorganic insulatormember and enclosed therewith in a conductive tubular enclosure formingsockets for and making electrical contact with the conductive balls.

The specification concludes with claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention. The invention may also be understood from the followingdescription taken in connection with the accompanying drawings in which:

FIGURE 1 is a partial cross-sectional view of a shielded conductor;

FIGURE 2 is an end view of a tubular insulator contained therein; and

FIGURE 3 is an end view of an alternative tubular insulator.

As shown in FIGURE 1, a first shielded conductor 10 comprising a firstinner conductor 11, a first rigid insulator 12, and a first outerconductor 13 are electrically connected to a second shielded conductor14 comprising a second inner conductor 15, a second rigid insulator 16,and a second outer conductor 17. Effectively, the first shieldedconductor 10 and the second shielded conductor 14 are coaxial lineselectrically connected by a shielded connector 18.

In order to provide the necessary flexibility in the electricalconnection, the shielded connector 18 utilizes two ball and socketelectrical connections comprising a first metal conductive ball 19contained within a socket formed by a tapered portion of a firstmetallic tubular member 20 of a conductive enclosure and a secondconductive or metal ball 21 and a socket formed by a tapered portion ofa second metallic tubular member 22 of the conductive enclosure. Thefirst conductive ball 19 and the second conductive ball 21 havediametrical apertures through which the shielded conductors 10 and 14respectively pass. In this manner, electrical contact is made betweenthe outer conductor 13 which shields the inner conductor 11 and theshielding ball and socket arrangement comprising the conductive ball 19and the tubular member 20. Similarly, an electrical connection is madebetween the outer conductor 17 shielding the inner conductor 15 and theball and socket combination comprising the conductive ball 21 and thetubular member 22.

The actual connection shielded by the connector 18 comprises aconductive member or Wire 24 connected to the inner conductor 11 and theinner conductor 15 by conventional techniques, as for instance spotwelding. The wire 24 spans a gap between the conductive ball 19 and theconductive ball 21, which gap is maintained by a tubular inorganicinsulator 25 which abuts the conductive balls 19 and 21 and prevents theinner conductive member 24 from electrically contacting the outertubular members 20 and 22.

The electrical connection may be mechanically secured by engagement of amale threaded portion 26 of the tubular member 20 and a female threadedportion 27 of the tubular member 22. The threaded engagement of thefirst tubular member 20 and the second tubular member 22 in combinationwith the tubular insulator 25 thereby retains the first conductive ball19 and the second conductive ball 21 in a spaced position. In order toretain the shielded conductor 10 and the shielded conductor 14 withinthe shielded connector 18 after extending a portion of each conductorthrough the conductive ball 19 and the conductive ball 21, portions 28and 29 of the outer conductors 13, 17 respectively, are flared. In orderto prevent the shielded conductors 10 and 14 from extending too farwithin the shielded connector 18, small sleeves 33 and 34 are attachedto the outer conductors 13 and 17 respectively, after assembly of theconnector is completed. Sleeves 33 and 34 may comprise any suitablemetallic material or nonmetallic inorganic material and may be securedto members 13 and 17 in a conventional manner.

Thus, it may be seen that the shielded inner conductor 11 and theshielded inner conductor 15 are electrically connected through ashielded connection provided by the shielded connector 18, and morespecifically, by the conductive enclosure provided by the tubular member20, the tubular member 22, the conductive ball 19, and the conductiveball 21. Yet, in spite of the shielding of the electrical connection asprovided by the wire 24, the connection itself obtains the necessaryflexibility which may be ascertained by observing the illustratedangular displacement between the axes of the shielded conductor 10 andthe shielded conductor 14. The range of angular displacement is limitedby interference of the flares 28 and 29 with the insulator 25, or byinterference of the sleeves 33 and 34 with the tapered ends of thetubular members 20 and 22, respectively. In order to increase the rangeof angular displacement the tubular members 20 and 22 have beveled ends30 and 31, respectively. Of course, the bakeability requirement isreadily obtained since the conductive enclosure, the metallic tubularinsulator 25, and the wire 24 are not subject to emission ofcontaminating vapors as an organic enclosure would be.

The precise shape of the insulator 25 may be dictated by the particularassembly technique utilized. When the tubular member 25 is solid asshown in FIGURE 2, the spot welding of the wire 24 to the conductors 11and 15 can be made after the tubular insulator 25 is insertedintoposition and slid back with the conductive ball 19 along the outerconductor 13. After wire 24 is connected, the ball 19 and insulator 25are slid toward the flare 28 so that threads 26 and 27 can be engaged.If a slotted tubular insulator 32, as shown in FIGURE 3, is utilized,both spot Welds of the wire 24 may be made before the insulator 25 isplaced in position. In either case, the axial positions of the shieldedconductor 10 and the shielded conductor 14 must be determined prior totightening the threaded engagement between the tubular member 20 and thetubular member 22 since the insulator 25 or the insulator 32 serve toretain the conductive ball 19 and the conductive ball 21 in fixedpositions after tightening.

It is appreciated that alternative means for attaching the tubularmember 20 and the tubular member 22 are available through conventionalthreaded fastening techniques. It is, of course, not intended to limitthe invention to the particular fastening technique shown but rather todisclose one form of inexpensive means for fastening the shieldingconductive enclosure.

Although the invention as described has been concerned with provisionfor a shielded connection between two .4 shielded conductors, theinvention is readily adaptable to certain forms of RF transmission.While particular frequencies of RF transmission might be found to beinapplicable due to the discontinuities in the particular ball andsocket arrangements, RF transmission at many frequencies can be effectedthrough the shielded connector 18 as shown. Since the intent of theabove discussion has been to disclose a low cost shielding connector,there has been no attempt to design around the discontinuities whichmight impair transmission of particular frequencies.

Although specific embodiments of the invention have been shown anddescribed, it is not desired that the invention be limited to theparticular form shown and described, and it is intended by the appendedclaims to cover all modifications within the spirit and scope of theinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A shielded connector for electrically connecting a first shieldedconductor comprising a first inner conductor and a first outer conductorwith a second shielded conductor comprising a second inner conductor anda second outer conductor comprising:

a first conductive ball with a first aperture therethrough and a secondconductive ball with a second aperture therethrough the first shieldedconductor being inserted through the first aperture and the secondshielded conductor being inserted through the second aperture,

a conductive enclosure enclosing and contacting said first conductiveball and said second conductive ball comprising a pair of interfittingsleeves having inwardly tapered ends engaging the remote outer surfacesof said conductive balls,

an inorganic tubular member positioned within said interfitting sleevesand engaging adjacent outer surfaces of said conductive balls tomaintain said balls at a fixed distance,

a flexible conductor connected between said inner conductors, and

adjustable sleeves encircling said shielded conductors for preventingmovement of said conductive balls along said outer conductors.

2. The shielded connector of claim 1 in which said interfitting sleeveshave a threaded connection and said flexible conductor is folded and hasan extended length greater than said fixed distance whereby connectionof said flexible conductor to said inner conductors may be made aftersaid inorganic tubular member is placed between said conductive balls.

3. The shielded connector of claim 1 in which said inorganic tubularmember has a longitudinall extending slot.

References Cited UNITED STATES PATENTS 1,927,703 9/1933 Glowacki.

FOREIGN PATENTS 545,514 7/1922 France.

DARRELL L. CLAY, Primary Examiner US. 01. X.R, 174 91; 339-7

